Can't work out how to amend this?

JavaScript
1

Have been trying to amend the code below to take out all options for 6 monthly and getting stuck - can anyone advise please

<script language="javascript">
var rdVal='M';
function selPrice(x)
{
rdVal=x;
	if(x=="M")
	{
	document.getElementById("monthRate").style.display='';
	document.getElementById("6monthRate").style.display='none';
	document.getElementById("yearRate").style.display='none';
	
	document.getElementById("a3").value=document.getElementById("monthRate").value;
	document.getElementById("p3").value='1'; //Monthly


	}
	else if(x=="Y")
	{
	document.getElementById("monthRate").style.display='none';
	document.getElementById("6monthRate").style.display='none';
	document.getElementById("yearRate").style.display='';

	document.getElementById("a3").value=document.getElementById("yearRate").value;
	document.getElementById("p3").value='1'; //Yearly
	}
	
	else if(x=="M6")
	{
	document.getElementById("monthRate").style.display='none';
	document.getElementById("6monthRate").style.display='';
	document.getElementById("yearRate").style.display='none';

	document.getElementById("a3").value=document.getElementById("6monthRate").value;
	document.getElementById("p3").value='6'; //6 Monthly
	}
}

function chkVal()
{
	if(rdVal=="M")
	{
	document.getElementById("a3").value=document.getElementById("monthRate").value;
	document.getElementById("p3").value='1'; //Monthly
	}else if(rdVal=="Y")
	{
	document.getElementById("a3").value=document.getElementById("yearRate").value;
	document.getElementById("p3").value='1'; //Yearly
	}
	else if(rdVal=="M6")
	{
	document.getElementById("a3").value=document.getElementById("6monthRate").value;
	document.getElementById("p3").value='6'; //6 Monthly
	
	}

}
</script>
2

Can you please show us the HTML code that the script works with, or even better, link us through to a test page on the web that demonstrates the problem.